The unique traits of each individual form a common basis for distinguishing one person from another. For example, people are easily identified by physical traits which can be easily distinguished by the visual senses. The vocal characteristics of a person can also be used to distinguish one person from another. In a business or commercial sense, individuals can be distinguished by ascribing numbers or other data to the individuals. For example, a person's social security number or driver's license number can be used to identify an individual, irrespective of any physical characteristics.
In some situations the identity of an individual is required to facilitate a transaction, while in other situations the identity of the individual becomes necessary before a response can occur. For example, secret codes or numbers are sometimes utilized as the identifying indicia in order to complete banking transactions using electronic tellers. In other situations, the entrance to secure areas requires the positive identification by a security guard, or other electronic device. While there are a myriad of techniques and devices for generally identifying individuals, such techniques are generally either complicated and costly, or require other human intervention, such as a security guard.
One approach for identifying individuals utilizes the speech or voice traits of the individuals as the characteristic trait. In such type of system, a person who desires or requires identification or verification simply voices words, numbers or phrases as an input to the system. Various parameters of the spoken words are compared with a voice specimen previously processed and stored, whereupon the electronic equipment provides an indication as to whether a positive or negative identification has been made. The quantizing and characterization of speech information for speaker verification is the subject matter of much current theorizing.
In contrast with speech recognition systems which can decode speech signals to decipher English words, irrespective of the person who voices the words, speaker verification systems heretofore developed are in an infant stage and are not as well developed. A common problem with speaker verification systems is that in order to be reliable, a positive verification of a speaker's voice must be made irrespective of background noise, differences in the spoken phrase and slight variations in the speaker's cadence, tone, inflection, etc.
From the foregoing, it can be seen that a need exists for an economical and reliable speaker verification system which provides a high degree of acceptance of true speakers, and a high degree of rejection of impostor speakers. There is an associated need for a speaker verification system which is user-friendly, portable, cost effective, and which can be implemented with program-driven computers or processors.